The Open Systems Interconnection Reference Model (OSI Reference Model or OSI Model) is an abstract description for layered communications and computer network protocol design. It was developed as part of the Open Systems Interconnection (OSI) initiative. In its most basic form, it divides network architecture into seven layers which, from top to bottom, are the Application, Presentation, Session, Transport, Network, Data-Link, and Physical Layers. It is therefore often referred to as the OSI Seven Layer Model.
The application layer is the OSI layer closest to the end user, which means that both the OSI application layer and the user interact directly with the software application.
The Presentation Layer establishes a context between Application Layer entities, in which the higher-layer entities can use different syntax and semantics, as long as the Presentation Service understands both and the mapping between them.
The Session Layer controls the dialogues/connections (sessions) between computers. It establishes, manages and terminates the connections between the local and remote application.
The Transport Layer provides transparent transfer of data between end users, providing reliable data transfer services to the upper layers. The Transport Layer controls the reliability of a given link through flow control, segmentation/desegmentation, and error control.
The Network Layer provides the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks, while maintaining the quality of service requested by the Transport Layer. The Network Layer performs network routing functions, and might also perform fragmentation and reassembly, and report delivery errors. Routers operate at this layer-sending data throughout the extended network and making the Internet possible.
The Data Link Layer provides the functional and procedural means to transfer data between network entities and to detect and possibly correct errors that may occur in the Physical Layer.
The Physical Layer defines the electrical and physical specifications for devices. In particular, it defines the relationship between a device and a physical medium. This includes the layout of pins, voltages, cable specifications, Hubs, repeaters, network adapters, Host Bus Adapters (HBAs used in Storage Area Networks) and more.
The Entire Networking in inside world are networked between the different Sub personalities and different working hardware’s (organs), ……. TBC
Do each organ new that they were designed to be a part of the human body? If there was no human body whats and where is the place to those cells or organs? This reminds me of the greatly debated liner, egg or the chicken first? Organ or the body?
The TCP/IP Suite defines a set of rules to enable computers to communicate over a network. TCP/IP provides end-to-end connectivity specifying how data should be formatted, addressed, shipped, routed and delivered to the right destination. The specification defines protocols for different types of communication between computers and provides a framework for more detailed standards.
The Link Layer is the networking scope of the local network connection to which a host is attached. This regime is called the link in Internet literature. This is the lowest component layer of the Internet protocols, as TCP/IP is designed to be hardware independent.
The Internet layer (or Network Layer) solves the problem of getting packets across a single network.
The Transport Layer can be thought of literally as a transport mechanism e.g. a vehicle whose responsibility is to make sure that its contents (passengers/goods) reach its destination safely and soundly, unless a higher or lower layer is responsible for safe delivery.
The Application Layer refers to the higher-level protocols used by most applications for network communication. Examples of application layer protocols include the File Transfer Protocol (FTP) and the Simple Mail Transfer Protocol (SMTP). Data coded according to application layer protocols are then encapsulated into one or (occasionally) more transport layer protocols (such as the Transmission Control Protocol (TCP) or User Datagram Protocol (UDP)), which in turn use lower layer protocols to effect actual data transfer.
The Noble Truth Of Sufferings
What is the Noble Truth of Sufferings?
Birth is suffering, ageing is suffering, sickness is suffering, dissociatiom from the loved one is suffering, not getting what one wants is suffering: in short this five categories affected by clinging are suffering. There is this Noble Truth of Suffering: such was the vision, insight, wisdom, knowing and light that arose in me about things not heard before.
This Noble Truth must be penertrated by fully understanding suffering: such was the vision, insight, wisdom, knowing and light that arose in me about things not heard before.
(Samyutta Nikaya LV1,11)